Internal-combustion engine



Nova 2(), 1928. 1,692,025

E. R. BURTNETTV INTERNAL COMBUSTION ENGINE Filed 00%,. 23, 1924 M/[A rae,

m m (y N N \x f. E m r/vfrz I W/ wavy Patented Nov. 20, 1928.

UNITED STATES PATENT OFFICE.

EVERETT R. BURTNETT, OF LOS ANGELES, CALIFORNIA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO THE AUTOMOTIVE VALVES 00., OF LGS ANGELES, CALL FORNIA, A VOLUNTARY TRUST.

INTERNAL-COMBUSTION ENGINE.

Application filed October 23, 1924. Serial No. 745,343.

My invention relates generally to internal combustion engines of the two stroke cycle type, and more particularly to an engine poW- er unit having three cylinders, the head ends of two of which are connected by a common clearance space, and said connected cylinders functioning as combustion cylinders, and the third cylinder of the unit functioning as a pumping cylinder for supplying gaseous fuel charges to the connected combustion cylinders.

The principal object of my invention is' to provide an engine of the character referred to with sleeve valves arranged in the pumping cylinder and in the combustion cylinder that receives the gaseous fuel charges from said pumping cylinder, said sleeves being operated by suitable means driven from the crank shaft of the engine and at the same speed thereof, the sleeve within the pumping cylinder controlling the inlet of gaseous fuel thereto and the sleeve within the combustion cylinder controlling the transfer of gaseous fuel charges that are delivered from the pumping cylinder through a transfer duct and inlet ports into said combustion cylinder.

The structure herein illustrated, described and claimed is an improvement on the engine disclosed in my copending application filed September 18, 1924, Serial No. 738,419, and also the application filed jointly by myself and Homer A. Brunell, October 8th, 1924, Serial No. 742,391.

WVith the foregoing and tures of construction and arangement of parts which will be hereinafter described. and claimed, reference being had to the accompanying drawings, in which Figure 1 is a vertical section taken lengthwise through the center of the three cylinders of an engine of my improved construction;

Figure 2 is a transverse cross section taken on the line 22 of Figure 1;

Figure 3 is a transverse cross section taken on the line 33 of Figurel. H 9

Referring by numerals to the accompanying drawings which illustrate a practical embodiment of my invention, 10 designates a cylinder block in which is formed a gaseous fuel pumping chamber 11 and a pair ofcombustion chambers 12 and 13, the axes of'all of said chambers being parallel with each other,

other objects in- View, my invention consists in the novel feapiston 19 is arranged for reciprocatory move- 5 I ment withm the pump1ngchamber11,and said piston is connected to crank 17 by 2. connecting rod 20. I Pistons 21 and 22 are arranged for reciprocatory novement respectively with in combustion chambers 12 and 13, and said pistons areconnected by suitable connecting 7 rods, such as 23, to crank 18.

Secured to the central portion of crank 18 and between the bearings thereon that receive the connecting rods 23, is a counterbalancing member 24 that is designed to counterbalance the weight of the connecting rods 23 and pistons 21 and 22 so as to minimize vibration of the crank shaft during engine operation.

Formed through the upper portion of the wall of the pumping cylinder are gaseous fuel inlet ports 25 that are connected to a suitable source of gaseous fuel. supply, for instance a carburetor. F ormed'through the upper portion of the wallbetween pumping chamber 11 and combustion chamber 12 is a gaseous fuel transfer duct 26 that leads to an annular chamber27 that surrounds the upper portion of said combustion chamber 12, and leading from said annular chamber into the upper portion of said combustion chamber 12 are gaseous fuel inlet ports 28. Formed through thewvall that surrounds combustion chamber 13 is an exhaust port 29, the same being located so that it is uncovered and open only while piston 22 is passing low or outer center.

Arranged for- 'reciprocatory movement Within the combustion chamber 12 and surrounding piston 21 therein is a sleeve 30 which, by its reciprocating movement, alternately covers anduncovers the inlet ports 28 that admit gaseous fuel charge from thc pumping cylinder to combustion chamber 12. This sleeve is reciprocated in any suitable manner in proper time relation to'the movements of the pistons 19, 21 and 22, but I prefer to reciprocate said sleeve by the means illustrated in Figure 2, and which includes a link connection, such as 31, to a crank or an eccen tric shaft 32 that is driven directly from and at the same speed with crank shaft 14:.

Secured on top of the cylinder block lO-is a head block 33 in the under side of which is formed a pocket or recess 3 f that coincides with and constitutes a clearance space at the upper or inner end of pumping cylinder chamber 11. Formed in the under side of the a central portion of headblock33 is a shallow chamber 35 that constitutes an extension or clearance chamber for the head or inner end of combustion chamber 12, and leading from the side of this clearance chamber 35 to the immediately adjacent side of combustion chamber 12 is a shallow lateral extension or throat 36, the bottom of Which is inclined.

The chamber 35 and lateral extension 36 constitute ac'omm'on clearance space for the head or inner ends of the combustion chambers 12 and 13, and seated in head 33 above combus tion chamber 12 is an ignition device such as a spark plug 37, the; inner ends of the electrodes valve is preferably actuated by means of a link connection to eccentric shaft 32 and theparts being arranged so that said sleeve is drawn downwardly a sufficient distance to wholly uncover the inlet ports at the time pumping piston .19 is at low center or the outer end of its stroke.

During the operation of my improved en gine eccentric shaft 32 is driven simultaneou'sly and at the same speed with crank shaft 14;, andconsequently the sleeve valves 'and 39 move in proper time relation with the pistons 19 and 21. ll hile'pumping piston 19 is at low center or at the outer end of its stroke sleeve valve 39 is at the lower end of its travel; thereby uncovering inlet ports 25 and admitting to pumping chamber 11 a charge of gaseous fuel. As pumping piston .19 and sleeve valve39 start to move upwardly or in war'dl'y the inlet ports 25 will be closed and the charge ofrgaseous fuel will be compressed to acertain degree within the upper portion of the chamber 11 and in clearance space 3 f. During this upward travel of the pumping piston and sleeve surrounding the same the pistons 21'and 22 in the combustion-cha'ii'ioe'rs are 1 moving downwardly on their power stroke, and as said pistons approach low center sleeve 30 that surrounds piston 21 will pass below and uncover transfer inlet ports 28 and the compressed gaseous fuel charge from the pumping chamber will pass through ducts 38 and 26 to annular chamber 27, and

' said gaseous fuel will pass into the upper por-,

tion of combustion chamber 12 through the uncovered inlet ports 28. Piston '22 passes low center thereby uncovering exhaust port 29 at the same time transfer inlet ports 28 are uncovered, and the gaseous fuel charge entering the upper portion of chamber 12 will pass upwardly therethrough, thence tli'roiilgh clearancespace and throat 36 to combustion chamber 13, and thence downwardly through the latter to exhaust port 29. In thus moving through the combustion chambers and clearance space connectinghead ends thereof the admitted gaseous fuel charge will drive before it a substantial amountof the burnt gases and products of combustion resulting from the previously ignited fuel charge the same being expelled through exhaust port 29. At the beginning of the upward travel of pistons 21 and 22 and sleeve valve 30 the transfer inlet ports 28 will be closed, and as the combustion pistons continue to move upward or inward the gaseous fuel charge and the relatively small proportions of residual products of'combustion will be compressed within the upper portions of the combustion chambers and in the. clearance space connecting the same until" at the point of highest compres'siom or when the co-n'ibustion pistons pass high center the'coInpressed gaseous fuel charge will be ignited by a spark produced between the terminals of the electrodes ofplugs 37 and the expansion fol-' lowing combustion of the gaseous fuel charge will be directed against the heads of pistons 21 and 22 to move the same downward on their power stroke.

During the inward or compression stroke of the pistons 21 and 22 pumpingipiston 19 and sleeve valve 39 are moving downward or outward until, as they pass lowv or outer center, inlet ports'25 are uncovered, thereby admitting to the pumpin chamber a fresh gaseous fuel charge and the cycles of operations as heretoforedescribedare repeatedj Thus it will be seen that I have provided a relatively simple andpractical internal com bustion engine power unit that comprises a pair of connected combustion cylinders and apumping cylinder and the inlet of gaseous fuel into the pumping cylinder and the trans fer of the gaseous fuel charges from the pumping cylinderto' one of the combustion cylinders being controlled by sleeve valves that reciprocate in proper time relation to the movement of the pistons; with which said sleeve valves areassociated. V r v 1 Obviously, minor changes in the size, form and construction of the various parts of my improved internal combustion engine may be made and substituted for those herein shown Ill) llf)

Ill

and described without departing from the spirit of my invention, the scope of which is defined in the appended claim.

I claim as my invention:

In a two stroke cycle internal combustion engine, a pair of combustion chambers and a pumping chamber, a head closing all of said chambers, there being a pocket formed in the underside of said head for connecting the head ends of the combustionchambers and providing a common compression and combustion clearance chamber for said combustion chambers, there being a recess formed in said head, which recess 1s coincident wlth and constitutes a head extension for the pumping chamber, a duct leading from the recess in the head above the pumping chamber clownwardly through the wall between said pumping chamber and the adjacent combustion chamber, the lower end of which duct communicates with the combustion chamber in a plane below its upper end, an'inlet port formed through the wall of the pumping chamber at a point below its lower end, a

sleeve valve arranged for reciprocatory movement within the pumping chamber for controlling the charge volume inlet port thereto, a sleeve valve arranged for reciprocatory movement within the combustion chamber that is connected by the duct tosaid pumping chamber, which last mentioned sleeve valve controls the inlet of pumped fuel charges to the combustion chambers, pistons arranged for operation within the three chambers, a

crank shaft to which said pistons are connected, a crankshaft having two throws arranged 180 apart, connections between the pistons within the combustion chambers and one of said cranks, a connection from the piston in the pumping chamber and the other one of the two cranks and a diametrically arranged counterbalancing weight mounted on the intermediate portion of the crank to which the pistons in the combustion chambers are connected.

, In testimony whereof I aflix my signature.

EVERETT R. BURTNETT. 

